A laminated fabric for use as the fabric upper of shoes

ABSTRACT

A laminated fabric, suitable for use as the fabric upper of shoes, is prepared by bonding a layer of foam to the woven fabric, which will form the shell or outer covering of the shoe and, while the foam is still wet, bonding a second layer of fabric, which will form the inner lining or sock, to the foam and curing the thus-formed laminate. In a preferred embodiment a tiecoat which can be, for example, a solution of an aliphatic isocyanate, is applied to the woven shell fabric to also improve adhesion of the foam to that fabric and also to the thermoplastic sole and heel material used to make the shoe.

United States Patent Davis et a1.

[54] A LAMINATED FABRIC FOR USE AS THE FABRIC UPPER OF SHOES [72]lnventors: Delbert A. Davis, Kemersville; Samuel R. Averette, Wilson,both of NC; Gary Dwight Voss, El Paso, Tex. [73] Assignee: BurlingtonIndustries, Inc., Greensboro,

[22] Filed: Sept. 23, 1969 [21] Appl. No.: 860,421

[52] U.S.Cl ..l6l/88, 36/45, l'l7/l1,l56/331,161/159,161/165,161/182,l61/190,

[51 Int. Cl ..B32b 5/18 [58] FieldofSeareh ..l6l/l59-161, 165,

[56] References Cited UNITED STATES PATENTS 3,251,727 5/1966 Reynolds eta] ..16l/159 X 1 Feb. 15, 1972 2,792,320 5/1957 Bower ..161/96 X3,496,000 2/1970 Hull et al. ....161/159 X 2,721,811 10/1955 Dacey et al..1 17/65 3,422,165 l/l969 Brotherton et a1... ....161/l90 X 2,838,4186/1958 Starkweather, Jr.. ....260/429.5 X 3,362,036 1/1968 Swan et al..l61/l90 X 3,130,505 4/1964 Markevitch ..16l/159 X PrimaryExaminer-Philip Dier Attorney-Cushman, Darby & Cushman [5 7] ABSTRACT Alaminated fabric, suitable for use as the fabric upper of shoes, isprepared by bonding a layer of foam to the woven fabric, which will formthe shell or outer covering of the shoe and, while the foam is stillwet,bo nding a second layer of 2 Claims, No Drawings LAMINATED FABRICFOR USE AS THE FABRIC UPPER OF SHOES This invention relates to alaminated fabric suitable for use as the uppers" in fabric shoes such astennis shoes having, in particular, molded rubber or plastic toe, sole,and heel portions. More particularly, this invention relates to alaminated fabric comprising two layers of textile material with a layerof high-density foam material bonded between them.

It is commonly the practice in the manufacture of shoes having fabricuppers such as, for example, tennis or other athletic shoes, to firstprepare the fabric upper and place it around a form which is insertedinto a mold for making the toe, heel and sole portion of the shoe.Liquid plastic or rubber, for example polyvinyl chloride, naturalrubber, acrylonitrile or styrene butadiene rubber, is then injected intothe mold at high pressure and at a temperature of about 350-400 F. forexample. Unless the form upon which the fabric upper has been placed andthe mold for the toe, heel and sole portion of the shoe, fit withinclose tolerances, the problem is encountered of spillage of the liquidmaterial being cast out of the mold onto the fabric upper.

In order to prevent the spillage of the liquid plastic or rubber, closetolerances are usually maintained between the fabric material, which hasbeen placed around the form, by employing fabrics having sufficientthickness to fit closely within the mold and thereby seal off the hollowportion of the mold in which the toe, heel and sole are cast from thefabric material forming the cloth upper of the shoe. The requisitethickness of material, which can be about 0.03-0.065 inches thick, isoften realized'by employing fabric made up of a number of layers ofmaterial. This procedure, however, has the disadvantage that it isrelatively expensive to build up a fabric laminate in this manner usingmultiple layers of fabric material.

Accordingly, it is an object of'this invention to provide a laminatedfabric comprising only two layers of textile material with a thirdintermediate layer of high density foam, bonded between the two layersof textile material to provide a laminated fabric having the necessarythickness to be suitable for use as the fabric uppers of shoes havingcast or molded rubber or plastic soles, such as, for example, tennis'orother athletic shoes. It is a further object of this invention toprovide a laminated fabric material suitable for use as the fabricuppers of shoes which breathes", can be repeatedly washed in hot water,and has the necessary resiliency to-maintain its shape. It is still afurther object of the present invention to provide improved adhesionbetween the fabric forming the upper" of the shoe and the molded toe,heel and sole portion of the shoe.

According to the present invention, a laminated material suitable, forexample, for use as the uppers of sneakers or other athletic shoes inwhich a fabric upper is bonded to a molded rubber or plastic toe, soleand heel portion, is prepared by first forming a high-density foam,casting the foam on to an outer or shell fabric (suitable procedures forcasting foams are, for example, described in U.S. Pat. No. 3,196,062 toKristal), and then, while that cast foam is still wet, placing on thewet foam the inside or backing fabric. The backing fabric adheres to thewet foam which is then heated to dryness and then cured.

Fabrics which can be employed as the outer or shell material, can be anyof the fabrics commonly employed in fabric shoes to form the uppers, forexample cotton, or a polyester (Dacron) and cotton blend. A commonlyemployed fabric for the shell of this type of shoe which has been foundto be particularly useful in the present invention is a 2% to 4% ounce50 percent polyester (Dacron), 50 percent cotton blend.

Suitable backing fabrics for the side of the laminate forming the insideof the shoe can be, for example, cotton duck or drill, nylon tricot, oracetate.

The foam employed according to the present invention should have a highenough density to stiffen the fabric sufficiently so that it willconform to the shape of the shoe yet be resilient enough that the shoewill be comfortable and pliant. Suitable foam can be either open orclosed cell foam, although the open cell foam is preferred since it willbreathe. Resilience of the foam is also important since the laminatedfabric of this invention must return to form to avoid wrinkling.Suitable foam densities can be, for example, between about 0.47 and 0.94g./cc., preferably about 0.65 and 0.84, and most preferably about 0.75g./cc. Other criteria for foams employed in the present invention arethat they be washable and resistant to temperatures at least as high asthose encountered in washing or during laminating of the sole and heelsection of the shoe to the fabric upper (about 375 F.); that the foam bemoisture resistant; that it have good adhesion to the fabrics employedas both the outer shell and inner lining without breaking down duringwashing, that the material have sufficient strength, particularly whereseams are formed, to withstand the strains induced during shoemanufacture by the equipment used in fabrication.

Foams suitable for use in the present invention, for example, thosedisclosed in U.S. Pat. No. 3,215,647, include styrene butadiene, vinylacetate, vinyl chloride and natural rubber or combinations thereof,which are mixed with about 3-7 percent by weight of a metallic soap ormixture of soaps which cause foaming on agitation, about 0.1 to 0.5weight percent of a release agent, such as, for example silicone, 1-5weight percent melamine resin, all weight percents being based on thetotal weight of the foam. Suitable polyurethane foams can also be used.The preferred foam, however, is a styrene butadiene-natural rubbercombination.

In one embodiment of the present invention, it has been foundparticularly desirable when employing blends of synthetic fibers as theshell material on to which the foam is deposited, such as for example acotton-polyester blend, nylon-cotton blend, or nylon-rayon blendfabrics, to first coat the fabric with a tiecoat which will inhibitmigration to the surface of the metallic soap used in the foam to causefoaming, as the migration of the soap to the surface adversely affectsadhesion of the foam to the shell fabric surface. It is, of course, alsodesirable to employ such a coating in the case of pure cotton fabrics,though the problem of migration of the soap toward the interface of thefoam and fabric, with subsequent impairment of bond strength, is not sogreat, as there is a greater degree of mechanical interlocking of thefoam and cotton fabric than is the case with synthetic blends whereadhesion is more dependent on the formation ofa chemical bond betweenfoam and the shell fabric. Where such mechanical adhesion is found, itis often sufficient to merely apply a vinyl chloride organisol.

In a further embodiment of the present invention, the adhesion to thesole and heel material of the fabric material forming the uppers" of theshoe is improved by the application also of a tiecoat to the shellfabric. As in the case of foam substrates, where mechanical adhesionbetween the shell fabric (for example cotton) and the sole material(which may be for example vinyl chloride or styrene butadiene) a vinylchloride organisol applied to the fabric may provide sufficientadhesion.

One suitable composition with which the material which is to form theouter shell of the shoe can be coated to improve adhesion of many foamsor sole materials (e.g., vinyl chloride, styrene butadiene, naturalrubber, or acrylonitrile sole material) to the shell comprises l-3weight percent, preferably about 2 weight percent of an organictitanate, to which can be added l-3 weight percent, preferably about 2-3weight percent of melamine formaldehyde resin, and the balance, asuitable organic solvent such as toluene, for example, or water.Suitable organic titanates for use to improve adhesion between substrateand sole material or foam have the formulas:

Ti(OR)., and Ti(OCOR){,,(OR),, where R is an alkyl group of two-20carbon atoms or a mixed or polymerized alkyl, aryl, or cycloalkyl group,and n is 0-3. Preferred titanates are tetraisopropyl titanate andtitanium acetyl acetonate.

Application of the organic titanate-melamine formaldehyde resin of thisinvention to the fabric can be by a variety of procedures such as, forexample pad-dipping" or by the "dip and nip" method, whereby the fabricis passed on rollers acetate containing a maximum of 20 percent vinylacetate and preferably a maximum of IO percent.

Typical plasticizers (e.g., organic phosphates, phthalates oracrylonitriles) are employed in the tiecoat and can be, for exthroughthe tiecoat bath and then under tension passes a rod 5 ample, dioctylphthalate, diiso-octyl-decyl phthalate and di-nor roller which removesthe excess. While a single pass of the octyl phthalate. Flame resistancecan be improved by using a fabric through the resin solution has beenfound satisfactory, p ph plaslicizer, for mpl tri-cresyl ph ph teseveralpasses can be made. Curing of the tiecoat impregnated Organic s cyan tesi h r empl yed in the tiecoat can fabric substrat can b ff t d, for a lb a ing h be either aromatic or aliphatic, though tiecoat compositionsmaterial through an oven or series of ov i i d at a containing aliphaticisocyanates are preferred over both the moderate temperature range ofabout 200 F. to 280 F. aromatic isocyanates and tiecoats previouslydescribed, which Table l illustrates the e io adhe io obt i d using acontain organic titanates and melamine-formaldehyde resin, coating oforganic titanate-melamine resin tiecoat: The formuas the alllJhallC yaat based mp Si i0n has been found lations w re a li d to a 65 percent t35 percent not to produce the yellowing associated with other tiecoats.cotton blend fabric substrate and dried in an air circulating yparomatic isocyanates are methylene -p y oven at about 260 F. and astyrene butadiene rubber foam apy and p b/ y e po yp enylisocyanate.Aliphatic plied and cured. isocyanates of this invention have thegeneral formula:

TABLEI O CN-R-NHC OIIIC ONH-R-NC O R Composition (weight k) A B C D 111C0 Mcktminc-Fnrmaldchydc Resin 0 2.0 2.0 2.0 Twaisnpwpyl "mm 0 0 2.0 3.0where R is an alkyl group of three eight, p eferably six, car Toluene 098.0 96.0 95.0 atoms- Adhesion oi'l'oam to substrate Once the tiecoathas been applied to the fabric, for examilhx-lsq- -l ple, by dip coatingand removing the excess either by the nip method of drawing the fabricunder tension over a straight edge or with pads, the coated fabric isdried in an oven Similar results were obtained with similar applicat onof the f a ff i period f time and at a ffi i tl high tetraisopropyltitanate-melamine formaldehyde resin tiecoat peramre to remove the SolveTypical] drying temperatures shown above and styrene-butadiene foam toother fabrics: Sh0u|d not exceed about 450 to avoid weakening thefabric. lfdesired, the drying can advantageously be carried out TABLE llin stages whereby the temperature is increased in increments. Foam isconveniently produced, for example, by mechani- I cal agitation, andthen deposited onto the woven fabric which Fabric Foam 'lj z' zl withnew" has been treated with the tiecoat. While the foam is still wet,polyester 30 inn the woven material which will form the inner liner ofthe shoe Nylon 75 1 40 or sock is placed on the wet foam and thelaminate then cured, for example in an oven at a temperature of about275 to 450 Nylon-Cotton 8.0 15.0 F If d d h l b ff d b 90 no esire ecuring may convenient y e e ecte y passing the laminate through a seriesof ovens at a controlled TABLE III Percent melamine- Sample formalde-Percent Type Type Adhesion, Number Fabric hyde resin titanate tyzorsolvent lbs/sq. in A Poplin, polyester cotton 2 1 Tetraisopropyltitanate .i Toluene" 9.3 B do 2 2 'Ietrabutyl titanate do. 17. 0 0.. 2 2'Ietrakls Z-ethylhexyltitanate do 17.0 D 2 2 Polymerized C4 titanate 16.6 E 2 2 Acetylacetonato 18.0 F 2 0 12.6 G 1 11.0 H 1 2 Tetraisopropytitanat 19.0

in a further embodiment of the present invention, it has' been foundthat the migration to the surface of soap present in the foam used inthis invention, with consequent decrease in adhesion between the foam orsole material and the fabric substrate can also effectively be inhibitedby the application to the substrate of a tiecoat containing about 2 to3.5 weight percent, preferably about 2.9 weight percent vinyl acetatecopolymer, about 1 to 2.2 weight percent, preferably about 1.8 weightpercent, of a suitable plasticizer and 0.2 to 0.4 weight percent,preferably about 0.3 weight percent of an organic isocyanate, the totalsolids content being between about 4 and 6 percent by weight in anorganic solvent such as, for example, toluene, Varsol. dimethylformamide, methyl ethyl ketone or mixtures thereof.

The preferred vinyl acetate copolymers employed in this invention toform the tiecoat are high molecular weight vinyl ucetate-acrylonitrilecopolymers containing about 39 percent acrylonitrile and a copolymer ofvinyl chloride and vinyl rate, the ovens being maintained at peratureswithin the indicated range.

progressively higher tem- EXAMPLE was dip coated by total emersion ontoa 50-50 polyester-cotton blend woven fabric and the excess removed withpads. The

tiecoat was then dried by passing the coated fabric through a series ofovens for a distance of I50 ft. at a speed of 40 yards/minute. The ovenswere maintained at consecutive temperatures of 275 F., 325 F. and 375 F.Subsequent to drying of the tiecoat, a carboxylated styrene-butadienerubber foam having a density of 0.75 g./cc. and containing 0.3 weightpercent silicone release agent and about 5 percent by weight of ametallic soap, was formed by mechanical agitation and applied to thedried polyester and cotton fabric impregnated with the tricot. While thefoam was still wet a nylon tricot fabric was placed over it, and thelaminated fabric comprising the two outer layers of nylon tricot andpolyester-cotton, respectively, with the foam intermediate layer passesto an oven for drying and curing. Drying of the foam was carried out atabout 250 F. for 2 minutes and curing at about 360 F. for 4 minutes. Theresulting laminated fabric showed a bond strength between sole materialand polyester-cotton of 13-19 lbs/sq. inch.

We claim:

1. A laminated fabric comprising a first layer of a woven fabric ofpolyester and cotton, an intermediate layer of cured styrene-butadienefoam containing 37 weight percent of a metallic soap, 0.l to 0.5 weightpercent of a release agent and l to 5 weight percent melamine resin,said foam being bonded to the polyester-cotton fabric by means of atiecoat which has been applied to said fabric and which comprises asolution comprising 0.2 to 0.4 weight percent of an aliphatic isocyanatehaving the formula 2 to 3.5 weight of a vinyl acetate-vinyl chloridecopolymer, and about 1 to 2.2 weight percent dioctyl phthalate in methylethyl ketone, and a layer of woven nylon tricot also bonded to saidintermediate layer of foam, the total thickness of the laminated fabricbeing about 0.03 to 0.065 inches.

2. A laminated fabric suitable for use as the fabric uppers of shoescomprising a first layer of woven fabric, a second, intermediate layercomprising a cured high density, open cell foam bonded to said firstlayer, and a third woven fabric layer which is also bonded to saidintermediate layer of foam, the total thickness of said laminated fabricbeing from about 0.03 to 0.065 inches, said foam having a density ofabout 0.47 to 0.94 g./cc. and comprising an elastomer selected from thegroup consisting of styrene-butadiene, vinyl acetate, vinyl chloride,and natural rubber or mixtures thereof in combination with about 3-7weight percent of a release agent and 1-5 weight percent melamine resin.

2. A laminated fabric suitable for use as the fabric uppers of shoescomprising a first layer of woven fabric, a second, intermediate layercomprising a cured high density, open cell foam bonded to said firstlayer, and a third woven fabric layer which is also bonded to saidintermediate layer of foam, the total thickness of said laminated fabricbeing from about 0.03 to 0.065 inches, said foam having a density ofabout 0.47 to 0.94 g./cc. and comprising an elastomer selected from thegroup consisting of styrene-butadiene, vinyl acetate, vinyl chloride,and natural rubber or mixtures thereof in combination with about 3-7weight percent of a release agent and 1-5 weight percent melamine resin.